Global efforts to identify and develop soil quality indices that can accurately and efficiently quantify effects of soil and crop management began to emerge around the world during the latter portion of the 20th century. This occurred as people became more aware that soil is a unique, nonrenewable resource that nurtures and sustains human civilizations (McNeill and Winiwater, 2004). These efforts have been further encouraged by a growing awareness of the multiple ecosystem services that soil resources provide to sustain food security, environmental quality, ecological functions, and most recently feedstock production for biofuels (Doran et al., 1996; Bouma, 2005; Lal, 2007). In addition to serving as assessment tools, soil quality indices also provide land managers with a better understanding of how their short-term, economically driven management decisions are affecting soil properties and processes over time.